Gerben,

I do not know if it is possible with Context. 

But this definitely works with an xsl operation. 

You will need an xsl file like this:

myxslfile.xsl:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<xsl:output method="xml" indent="yes" omit-xml-declaration="yes"/>

  <xsl:template match="contacts">
  <xsl:for-each-group select="contact" group-by=“contact/@ad">
    <xsl:result-document href="groep-{current-grouping-key()}.xml">
       <contacts>
         <xsl:copy-of select="current-group()"/>
       </contacts>
    </xsl:result-document>
  </xsl:for-each-group>
</xsl:template>
<!-- alleen met Saxon, xslt: versie 2 -->

</xsl:stylesheet>


myxmlfile.xml

<contacts>
<contact>
<name ad=“BAR">John</name>
</contact>
<contact>
<name ad=“BAR”>Gerben</name>
</contact>
</contacts>

Use it like this with saxon (xsl version 2).

saxon -xsl:myxslfile.xsl -s:myxmlfile.xml -o:dummy.xml

This program will generate an empty dummyfile.xml but also xml files, (e.g. BAR.xml) in which it will collect al contact that have @ad=‘BAR', and there will be as many files as you have different values of @ad in your xml file. I am very far from being a specalist on xsl, please refer for further information to xsl forums. Have fun experimenting!

I do this myself and then have a script generate the pdfs.

Hope this helps.

Robert



> Op 15 apr. 2020, om 14:13 heeft Gerben Wierda <gerben.wierda@rna.nl> het volgende geschreven:
> 
> 
> 
>> On 15 Apr 2020, at 13:54, Wolfgang Schuster <wolfgang.schuster.lists@gmail.com <mailto:wolfgang.schuster.lists@gmail.com>> wrote:
>> 
>> Gerben Wierda schrieb am 15.04.2020 um 12:19:
>>>> On 14 Apr 2020, at 11:52, Taco Hoekwater <taco@elvenkind.com <mailto:taco@elvenkind.com>> wrote:
>>>>> On 14 Apr 2020, at 11:25, Gerben Wierda <gerben.wierda@rna.nl <mailto:gerben.wierda@rna.nl>> wrote:
>>>>> 
>>>>> This helps for adding information to my processing.
>>>>> 
>>>>> What I was also looking for is that I don’t have a test.tex anymore, just the XML file I am parsing and a command line action.
>>>>> 
>>>>> So, I use mtxrun, give it the name of an XML. lua code (using a ’script’ somewhere?) reads the XML, extracts a name (e.g. ‘foo’) from it, creates a .tex file (e.g. ‘foo.tex’), produces a .pdf file from that .tex file (e.g. ‘foo.pdf').
>>>> When processing XML, I normally use
>>>> 
>>>>   context —environment=whatever.tex file.xml
>>>> 
>>>> with whatever.tex being a mix of tex and lua to setup and process the XML directly,
>>>> perhaps including other XML files as needed.
>>> But this means that the whatever.tex file needs to exist beforehand and the result is whatever.pdf
>>> 
>>> I want the actual PDF to be produced have a name that comes from the XML I am processing and thus the whatever.tex file be created by lua. There is no whatever.tex file before I run the command.
>>> 
>>> Pre-command:
>>> 	XML:
>>> 		contains file name “foo”
>>> 	there is no .tex file
>>> 
>>> Command:
>>> 	produces foo.tex (gets the name from the XML) and “foo.pdf"
>> 
>> The TeX file in Tacos example contains the xmlsetup entries which are used
>> to map the XML tags to ConTeXt commands and environment, the resulting
>> PDF file has the same name as the XML file.
> 
> That is different from
> 
> 	 the resulting PDF file has the name of an entry/field in the XML file.
> 
> So, what I am looking for is:
> 
> 	command foo.xml
> 
> which results in 
> 
> 	bar.pdf
> 
> where ‘bar’ is text in foo.xml
> 
> G
> 
>> 
>> Wolfgang
>> 
> 
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